Planar antenna for beam scanning

A beam scanning plane antenna configured by stacking, in order, a system connecting portion, a Rotman lens portion, and a beam scanning antenna portion,

• the beam scanning antenna portion including:
• a power feeding substrate containing a plurality of antenna groups that each include an irradiating element, a power feeding line connected to the irradiating element, and a first connecting portion connected electromagnetically to the Rotman lens portion;
• a first grounding conductor having a first slot at a position corresponding to the position of the irradiating element;
• a second grounding conductor having a second slot at a position corresponding to the position of the first connecting portion;
• a first dielectric provided between the first grounding conductor and the power feeding substrate;
• and
• a second dielectric provided between the power feeding substrate and the second grounding conductor,
• the Rotman lens portion including:
• a Rotman lens substrate having a Rotman lens pattern, a second connecting portion, which is connected to the Rotman lens pattern, for connecting the Rotman lens pattern with the first connecting portion, and a third connecting portion, which is connected to the Rotman lens pattern, for connecting the Rotman lens pattern with the system connecting portion electromagnetically;
• a third grounding conductor having a third slot at a position corresponding to the position of the third connecting portion;
• a third dielectric provided between the second grounding conductor and the Rotman lens substrate;
• and
• a fourth dielectric provided between the Rotman lens substrate and the third connecting conductor,
• wherein the Rotman lens portion and the beam scanning antenna portion are configured by stacking, in order, the third grounding conductor, the fourth dielectric, the Rotman lens substrate, the third dielectric, the second grounding conductor, the second dielectric, the power feeding substrate, the first dielectric and the first grounding conductor.